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再生纤维素膜及其微孔膜性能的比较 总被引:1,自引:1,他引:1
用微相分离法制奋不同孔径的再生纤维素微孔膜。由流速法和电子显微镜测定了它们的孔径,研究了它们的透过性和力学性能,并且与一般铜氨法再生纤维素膜进行比较。结果表明,该膜具有较好的力学强度和韧性,较高的筛分性,特别是这种膜的透水速度比一般膜高两倍。上述性能的改善可归因于微相分离法使膜形成大量直通孔道。此外,本文提出一种格子模型表示一般膜的孔径三维无规分布的维数k与膜孔隙率p_r之间的关系,由此对流速法测定平均孔半径的计算公式修正如下: 相似文献
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以常用廉价溶剂N,N-二甲基乙酰胺(DMAc)为介质,以纤维素和尿素为原料,制备了纤维素氨基甲酸酯(CC),采用红外光谱、X射线衍射、扫描电镜等对产物的结构进行了表征,并对纤维素再生膜的截留性能进行了研究。结果表明,制备纤维素氨基甲酸酯的最佳反应条件为160℃,8 h;酯化前后,纤维素晶型没有发生明显的变化;制备的纤维素再生膜具有孔径很小的微孔,这些微孔能够使H_2O和Na_2SO_4在压力的作用下顺利通过,而对亚甲基蓝有良好的截留效果;因此,纤维素再生膜对含亚甲基蓝的废水具有良好的分离效果。 相似文献
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基于再生纤维素基质组装的氨基硅膜形貌及其定向排列方式 总被引:2,自引:0,他引:2
用原子力显微镜AFM、光电子能谱仪XPS等研究了组装在再生纤维素基质(cel)表面的N-β-氨乙基-γ-氨丙基聚二甲基硅氧烷(ASO-1)的膜形貌、表面相化学组成及疏水性.结果发现,受基质表面不平整性的影响,组装在cel表面的氨基硅膜(ASO-1/cel),微观上会表现出一种类似于基质的粗糙形貌.而XPS分析和接触角测定结果表明,ASO-1/cel表面强烈疏水,在其表层明显存在由氨基硅ASO-1所产生的Si2p、Cls、Nls和Ols XPS峰.据此推测,ASO-1在cel表面的定向排列成膜方式为:硅甲基朝外伸向空气、Si-O偶极键以及极性氨基指向基质界面. 相似文献
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目的 为提高废弃棉织物的利用价值和利用率,将回收的废弃棉织物溶解于LiCl/DMAc溶液中,随后以水、体积分数为50%的乙醇水溶液、甲醇、乙醇、丙酮为凝固浴,通过溶胶–凝胶法成功制备高阻氧性再生纤维素(RC)薄膜。方法 采用氧气透过测试仪、水蒸气透过测试仪、拉伸测试仪、红外光谱和热重对RC膜的结构和性能进行探究。结果 不同的凝固浴条件下制备出的RC膜均具有极高的氧气阻隔性和较高的拉伸强度。其中丙酮为凝固浴的条件下制备出的RC膜的氧气阻隔性能最佳,其透氧系数可低至2.093 5×10−17 cm3.cm/(cm2.s.Pa),远低于相同测试条件下的普通塑料薄膜透氧系数2~4个数量级。此外,该薄膜还具有很高的力学性能,拉伸强度可达98 MPa,远高于普通聚乙烯薄膜的拉伸强度。结论 该工作制备了一种具有高阻氧性和高强度的可降解RC膜,这为废弃棉织物的回收和二次利用提供了一种新的途径。 相似文献
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采用碱/尿素/水体系对实验室自制的纤维素氨基甲酸酯(N%-1.8)在双螺杆中进行低温溶解,过滤、脱泡,得到清亮的纤维素氨基甲酸酯溶液。探讨制膜液浓度、凝固浴浓度、凝固浴温度,凝固时间对再生膜力学性能的影响,并结合FT-IR、XRD、SEM对膜的结构和形貌进行表征。结果表明,制膜液浓度为4.5wt%,凝固浴为H2SO4-8%、HOAc-16%和H2SO4/Na2SO4-7%/9%,凝固温度20~30℃,凝固时间为5min时所得的膜具有较好的力学性能,抗拉强度达到60~70MPa,断裂伸长率为6~10%。 相似文献
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采用DMAC/LiCl为溶剂,分别溶解纤维素与氨纶切片TPU,强烈机械搅拌共混均匀,以蒸馏水为凝固浴制备再生纤维素/TPU复合膜,用核磁共振1 H NMR分析谱图表征了TPU的结构特征,傅里叶红外光谱(FT-IR)、X射线衍射(XRD)、材料万能拉伸仪对复合膜的结构及强力性能进行了测试,采用WGT-S透光仪测定了复合膜的透光率,结果表明TPU引入纤维素矩阵中,一定程度上破坏了再生纤维素膜的结晶度,大大提高了再生纤维素膜的断裂伸长率,降低了其拉伸强度,当TPU加入量为20%(质量分数),再生纤维素膜的断裂伸长率提高到65%,透光率均保持良好。 相似文献
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Malgorzata Lisiska‐Kunierz 《Packaging Technology and Science》1999,12(4):179-183
Hydrophilic, regenerated cellulose films are characterized by certain adsorption properties. These investigations were aimed at determining to what extent the moisture content of a film might decide its barrier capacity against water vapour. The experimental materials were an unlacquered regenerated cellulose film and one varnished on both the sides with nitrocellulose lacquer. The investigations allowed us to propose some models that formally describe the adsorption process of water vapour through films at different values of ambient relative humidity. In addition, we determined the functional relation between the water vapour permeability of the films under investigation and their moisture contents and equilibrium ambient relative humidity values. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
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采用射频磁控溅射工艺,在柔性PET衬底上低温制备电致变色WOx/ITO/PET多层薄膜.利用X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)分析所制备薄膜的原始态、着色态和退色态的微观结构、表面形貌及W元素的化合价态.结果表明:原始态、着色态及退色态的WOx薄膜均为非晶态;原始态薄膜表面存在较多孔洞,薄膜在LiClO4的乙腈溶液中进行电致变色反应,实验发现着退色态薄膜颜色可发生可逆变化,随Li 的注入和抽出,薄膜表面形貌发生明显变化;XPS分析进一步表明WOx薄膜在原始态中W元素的化合价为W6 ,着色态存在W6 和W5 的混合价态. 相似文献
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Indium tin oxide (ITO) films were deposited on glass substrates by rf magnetron sputtering using a ceramic target (In2O3-SnO2, 90-10 wt%) without extra heating. The post annealing was done in air and in vacuum, respectively. The effects of annealing on the structure, surface morphology, optical and electrical properties of the ITO films were studied. The results show that the increase of the annealing temperature improves the crystallinity of the films, increases the surface roughness, and improves the optical and electrical properties. The transmittance of the films in visible region is increased over 90% after the annealing process in air or in vacuum. The resistivity of the films deposited is about 8.125×10−4 Ω cm and falls down to 2.34×10−4 Ω cm as the annealing temperature is increased to 500°C in vacuum. Compared with the results of the ITO films annealed in air, the properties of the films annealed in vacuum is better. 相似文献
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薄膜厚度对ITO膜结构与性能的影响 总被引:1,自引:0,他引:1
本文对所研究的直流磁控溅射法制备的ITO透明导电薄膜,采用X射线衍射技术进行了膜层晶体结构与薄膜厚度关系的分析, 并测量了薄膜电阻率及透光率随薄膜厚度的变化情况.实验结果表明,当控制薄膜厚度达70 nm以上时,可获得结晶性好、电阻率低和透光率高的ITO透明导电薄膜,所镀制的ITO膜电阻率已降到1.8×10^-4 Ωcm,可见光透过率达80%以上.最后还对所镀制的ITO透明导电薄膜的质量指标作了评估. 相似文献
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采用反应射频磁控溅射技术制备HfTaO薄膜,利用X射线衍射(XRD)分析了薄膜的微结构,通过紫外-可见光分光光度计测量了薄膜的透过谱,计算了薄膜的折射率和禁带宽度,利用原子力显微镜观察了薄膜的表面形貌。结果表明,随着Ta掺入量(10%,26%,50%)的增加,HfTaO薄膜的结晶化温度分别为800、900、950℃,Ta掺入量继续增加到72%,经过950℃退火处理的HfTaO薄膜仍然保持非晶态,具有优良的热稳定性。AFM形貌分析显示非晶HfTaO薄膜表面非常平整。在550nm处薄膜折射率n随着Ta掺入量的增大而增大,n的变化区间为1.90~2.15。同时HfTaO薄膜的光学带隙Eg随着Ta掺入量的增大而逐渐减小,Eg的变化区间为4.15~5.29eV。 相似文献
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Jin Chenggang Wu Xuemei Zhuge Lanjian Sha Zhendong 《Frontiers of Materials Science in China》2007,1(2):158-161
ZnO/SiC multilayer film has been fabricated on a Si (111) substrate with a silicon carbide (SiC) buffer layer using the RF
(radio frequency)-magnetron technique with targets of a ceramic polycrystalline zinc oxide (ZnO) and a composite target of
pure C plate with attached Si chips on the surface. The as-deposited films were annealed at a temperature range of 600–1000°C
under nitrogen atmosphere. The structure and photoluminescence (PL) properties of the samples were measured using X-ray diffractometry
(XRD), Fourier transform infrared (FTIR) spectroscopy and PL spectrophotometry. By increasing the annealing temperature to
800°C, it is found that all the ZnO peaks have the strongest intensities, and the crystallinity of ZnO is more consistent
on the SiC buffer layer. Further increase of the annealing temperature allows the ZnO and SiC layers to penetrate one another,
which makes the interface between ZnO and SiC layer become more and more complicated, thus reduces the crystallinities of
ZnO and SiC. The PL properties of a ZnO/SiC multilayer are investigated in detail. It is discovered that the PL intensities
of these bands reach their maximum after being annealed at 800°C. The PL peaks shift with an increase in the annealing temperature,
which is due to the ZnO and SiC layers penetrating reciprocally. This makes the interface more impacted and complicated, which
induces band structure deformation resulting from lattice deformation. 相似文献